Some parasites are innocuous or even beneficial to mammalian hosts. The gastrointestinal helminths modulate several important intestinal functions such as immunomodulation. In contrast، infections by pathogenic parasites are the cause of numerous epidemics and serious disease. The inflammatory response to infection must be tightly regulated in order to achieve pathogen clearance and at the same time avoid consequences of deregulated gene expression. The discovery in eukaryotic cells of small non-coding RNAs called microRNAs (miRNAs) has greatly expanded our understanding of the mechanisms that regulate gene expression. Recently، the miRNAs biosynthesis and mechanism of action are well documented. Regarding their mechanism of action، miRNAs most often silence gene expression following association with mRNA targets and Argonaute proteins (Ago)، thereby forming the miRNA-induced silencing complex (miRISC). Numerous miRNAs can also be identified in extracellular compartments for example when associated with Ago in plasma، or when contained within exosomes، small membrane vesicles that bud off the cell surface into the extracellular space. These biofluid miRNAs have increasingly been validated as robust biomarkers for disease and organ damage

Helicobacter pylori، a worldwide infection، is associated with several infectious diseases including gastric ulcer، peptic ulcer، and gastric cancer resulting from the cytotoxinassociated gene A (CagA). The purpose of this study was to evaluate the seroprevalence of anti-H. pylori and anti-CagA IgG antibodies in Iranian dyspeptic patients.

Methods

In this prospective epidemiological survey، a total of 659 patients were evaluated for the presence of general anti-H. pylori IgG، and then for anti-CagA IgG by two commercial ELISA kits.

Results

The prevalence of general anti-H. pylori IgG was 58.1% (383 of 659 patients) which increased progressively with age (P<0.05) and was not significantly influenced by the sex (P=0.08). The prevalence of anti-CagA IgG antibody in seropositive and seronegative patients for general H. pylori IgG was 52.9% (37 of 70) and 61.9% (13 of 21)، respectively.

Conclusion

This is the first report on the high prevalence of anti-CagA IgG in both seropositive and seronegative patients for general IgG، indicating the importance of this antibody in diagnosis of H. pylori positive patients after seroconversion of the general IgG.

Tetracycline is one of the important antibacterial agents which is used against various bacterial infections. Different bacterial species and strains convey various tetracycline resistance (tetr ) genes.

Objective

The present study was conducted to evaluate the occurrence of five tetr genes (tetA، tetB، tetC، tetD، and tetM) among Salmonella serovars obtained from humans and animals.

Materials and Methods

A total of 60 different Salmonella strains previously recovered from humans، poultry، and animals were subjected to polymerase chain reaction (PCR) and sequence analysis of the genes.

Results

In total، 6 strains were positive for the presence of tetA gene; three serotypes were also positive for the presence of tetC gene. The sequence analysis and phylogenetic tree showed similarities between the sequences of serovars in the present study and other Salmonella serovars and some other bacteria species in GenBank data.

Conclusion

The results showed the great distribution of tetracycline resistance genes among Salmonella serovars with different sources which could be the effect of widespread use of the antibiotic particularly in the animals breeding farms.

Foodborne diseases are one of the fundamental problems in the world. Salmonella is one of the most important foodborne bacteria، which is responsible for the prevalence of foodborne diseases in humans.

Objective

The aim of this study was to investigate the presence of Salmonella in distributed chicken meat in Mahabad city، Iran.

Materials and Methods

In this study، 100 samples of chicken meat were selected from Mahabad city and investigated for the presence of Salmonella. Each sample was cultured in selenite cystine medium and incubated at 37°C for 24 hours. Then the obtained colonies were cultured in MacConkey agar and Salmonella-Shigella agar. Finally، biochemical and antibiogram tests were performed on isolated Salmonella samples.

Results

Totally، 7 chicken samples (7%) were found to be contaminated with Salmonella. All of the isolated Salmonella samples were identified as Salmonella enteritidis. All of S. enteritidis isolates (100%) showed the highest resistance to erythromycin and ampicillin antibiotics. All of the tested isolates (100%) showed sensitivity to gentamicin.

Since the discovery of hybridoma cells، the uses of monoclonal antibodies (mAbs) are in vogue. Such antibodies with single isotype have high specificity. The developments in the field of cell culture and technology have led to the production of improved qualities of mAbs. In general، mAbs are important reagents used in biomedical research، as well as in targeted drug delivery systems.

Objective

The aim of this study was to apply different strategies to produce mAbs against proamastigote Leishmania infantum strain in Iran.

Materials and Methods

At first، standard strains were cultured and antigens of L. infantum were obtained. Afterward، BALB/c mice were immunized and antibody titers were determined. For hybridoma cell formation، isolated lymphocyte cells from spleen of immunized mice and myeloma cells were fused at the ratio of 10:1 in the presence of polyethylene glycol and followed by limiting dilution method for the isolation of monoclones.

Results

More than 20 positive monoclones were hybridoma، from which 3 clones had optical density over 1.5. We named these clones as 5D2 FVI6، 3G2 FV7، and 3G2 FV5 which were selected for limiting dilution. From these hybrids، anti-promastigotes L. infantum mAbs were obtained. The results of isotype determination showed IgG2b sub-class (and not IgG1، IgG2a and IgA) in 5D2 FV and 3G2 FVI monoclones.

Conclusion

This study produced mAbs against promastigotes of Iranian strain of L. infantum for the first time. These antibodies have reactivity against Iranian strain of promastigotes L. infantum and can be used in the diagnosis of visceral leishmaniasis.

In recent years، high attention has been given to the biological activities of natural compounds and their potential antimicrobial properties.

Objective

In this study، the antibacterial properties of the extracts from tissue and peptides of Cerastoderma and Didacna were studied.

Materials and Methods

samples of Cerastoderma and Didacna were collected and washed. Then، the soft tissues were cut and powdered، and concentrations of 16، 8، 4، 2، 1 and 0.5 of chloroform، ethanol and methanol، and in addition extract of enzymatic hydrolysis were prepared، and their antibacterial activities against Staphylococcus aureus، Escherichia coli and Salmonella paratyphi were investigated. The disc diffusion method was used for the evaluation of strains susceptibility. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were investigated for bacterial growth inhibition.

Results

Methanolic and ethanolic extracts from Cerastoderma demonstrated higher growth inhibitory effects compared to those from Didacna on E. coli and S. paratyphi and exhibited similar activities against S. aureus at concentrations 16 and 8 ug/mL. In addition، chloroform extracts of Cerastoderma and Didacna displayed similar inhibitory effects on S. paratyphi and S. aureus at concentrations 16 and 8 ug/mL which was a suitable effect، and the extract from Cerastoderma was more effective. MIC and MBC of methanolic extracts were at the lowest level، especially against S. aureus.

Conclusion

It was revealed that Cerastoderma and Didacna extracts were effective as antibacterial compounds on S. aureus، E. coli and S. paratyphi species as natural agents.

FBacterial lipopolysaccharide (LPS) is a large pathogen-associated molecule that affects both animals and humans.

Objective

The aim of this study was to assess the effect of diclofenac sodium on hematological parameters and inflammatory markers after intraperitoneal injection of LPS in rats.

Materials and Methods

Ninety-six male Wistar rats were divided randomly into 8 equal groups. Groups I، II، and III were only injected intraperitoneally (IP) with 100، 200، and 300 μg/kg LPS، respectively. Groups IV، V، and VI were injected with LPS at doses similar to the above groups plus diclofenac 2.5 mg/kg (IM). Group VII was injected only with diclofenac at the same dose and group VIII (control group) was injected with normal saline. Blood samples were collected from the rats in different times (0، 1، 6، and 24 hours) after injection.

Results

The results showed that white blood cell (WBC)، neutrophil، and lymphocyte counts significantly decreased in all groups at 1 and 6 hours after injection of LPS (P<0.05). The total leukocyte count، neutrophils، and lymphocytes increased at 24 hours after injection of LPS، in groups I، II، III، and VI (P<0.05). The C-reactive protein (CRP) levels at 6 and 24 hours after injection of LPS، in groups I، II، III، and VI، showed significant changes (P<0.05). The CRP level decreased in groups IV، V and VI (LPS + diclofenac) compared with the groups that were not injected with diclofenac (P<0.05). A significant increase was seen in fibrinogen level in all challenged groups (with or without diclofenac) at 24 hours after injection of LPS (P<0.05).

Conclusion

Injection of diclofenac together with LPS did not affect the leukocyte changes (total and different count) and plasma fibrinogen level in rats. Diclofenac was effective in preventing high CRP changes induced by injection of LPS.